a. Field of Invention
The invention relates generally to lever latches, and, more particularly to a lever latch for releasably latching a door to a corresponding door frame by providing a latch unit including a pivotally mounted trigger having a catch.
b. Description of Related Art
A need exists for an improved lever latch device that may be easily installed and operated, a device that includes fewer parts for ease of manufacturing, and a device that may be installed in a limited opening in a door (for example).
Trigger release lever devices are well known in the art and may be used for releasably latching doors, panels, windows and the like (as shown for example in FIG. 1). As shown in FIG. 2, an exemplary conventional trigger release lever latch, generally designated 1, includes a handle 2 in combination with a trigger 3. Handle 2 generally includes an extension 4 mounted thereto, which is adapted to engage a door frame 5 via adjustable bolt 6. Adjustable bolt 6 may be axially adjusted relative to extension 4 by rotating nuts 7 to loosen adjustable bolt 6 in order to adjust the height thereof, and subsequently rotating nuts 7 (in the opposite direction) to lock adjustable bolt 6 in place. Trigger 3, which is biased by a spring 8, is operably connected to handle 2 to release or prevent the release of handle 2 by means of nib 9 (on handle 2), which is insertable into notch 11 (on trigger 3). Conventional lever latch 1 further includes a rotatable lock cylinder 12 having L-shaped bracket 13 fixedly attached thereto. As shown in FIG. 3, L-shaped bracket 13 may be rotated between first and second orientations 14 and 15, respectively, to prevent or allow counter-clockwise pivoting of trigger 3 (relative to FIG. 2) about hinge 10. Specifically, as shown in FIGS. 2 and 3, L-shaped bracket 13 is in contact with contact member 16 in first orientation 14, and is rotated out of contact with contact member 16 in second orientation 15. Finally, conventional lever latch 1 also generally includes a slot 17 for insertion of a key (not shown) for rotation of lock cylinder 12.
In order to install the conventional lever latch 1 discussed above, generally, an opening having a width Al (see FIG. 3) is drilled or otherwise made in a door D (for example). Thereafter, conventional lever latch 1 is inserted into the opening and is held in place by top plate 18 having width A2 (see FIG. 4), which is greater than width A1 and a screw (not shown) for securing the housing to a door D (for example). It can be seen in FIG. 3 that in order to allow complete rotation of L-shaped bracket 13 from first orientation 14 to second orientation 15, the width of the opening must be at least A3 for door thickness greater than t (see FIG. 2). Thus, adequate installation of conventional lever latch 1, which requires an enlarged opening of width A3 or the like to allow free rotation of L-shaped bracket 13, can be quite complex and costly for the installer. Moreover, from a manufacturing standpoint, the manufacture and installation of L-shaped bracket 13 onto lock cylinder 12 can significantly increase the manufacturing cost of conventional lever latch 1, which may be manufactured by the thousands.
In the art, there currently exist various other conventional lever latches, as disclosed for example in U.S. Pat. Nos. 5,664,813, 5,638,709, 5,609,373 and 5,267,762. The lever latches disclosed in these Patents include basic components such as a trigger for operating a handle and a bolt to releasably latch a door to a corresponding door frame.
These conventional lever latches however have several disadvantages. Some of the key drawbacks generally include an excessive number of components, which can make the devices difficult and expensive to manufacture. Additionally, because of the excessive number of components, the odds of an essential component failing during normal usage is significantly increased, thus rendering the devices unreliable. Moreover, for the average consumer, conventional lever latch devices can be difficult to operate as they may require sophisticated installation and operation procedures.
The invention solves the problems and overcomes the drawbacks and disadvantages of the prior art by providing a lever latch, for releasably latching a door to a corresponding door frame, which is easier and relatively inexpensive to manufacture, and which is relatively simple to install and operate.
Thus an aspect of the invention is to avoid the need to cut an enlarged opening A3 (as discussed above), irrespective of the door thickness.
The invention accomplishes this by providing a lever latch that includes a housing mounted in an opening in the door and a handle pivotally mounted to the housing. The handle is rotatable between opened and closed positions, and is biased to the opened position by a torsion spring mounted to the housing and also includes a tongue, which is operable to maintain the handle in the closed position. The housing further includes a bolt pivotally mounted thereto. The bolt is adapted to engage the door frame when the handle is in the closed position and disengage the door frame when the handle is in the opened position. The bolt also includes an adjustment bolt mounted at an end thereof for permitting adjustable engagement of the bolt to the door frame. The housing yet further includes a trigger, pivotally mounted to the housing, and having a catch mounted thereon. The trigger is pivotable between first and second positions, and is operable to retain the handle when in the first position and release the handle when in the second position. The trigger is biased to the first position by a coil spring mounted to the housing. The housing also includes a pawl, having a cutout, rotatably mounted to the housing, and rotatable between unlocked and locked positions. In the unlocked position, the cutout is aligned with the catch to allow the trigger to pivot to the second position, and in the locked position, the cutout is out of alignment with the catch and the catch contacts a surface on the pawl to thereby prevent the trigger from being pivoted to the second position. Finally, the housing may also include a lock cylinder rotatably mounted therein, and fixedly attached to the pawl to rotate therewith.
In the above described lever latch, the latch components such as the housing, the handle, the bolt, the trigger and the pawl are made of aluminum, steel, or an equivalent metal, or of plastic, ceramic, or an equivalent material. The bolt and the handle may be manufactured as a one piece unit, or may be separately manufactured and thereafter joined together.
In yet another aspect of the invention, the invention avoids the need to cut an enlarged opening A3 (as discussed above), irrespective of the door thickness, by providing a lever latch including a housing and a latch mechanism including a handle and a bolt. The latch mechanism is operable to latch or un-latch the lever latch. The lever latch further includes a trigger mechanism, mounted to the housing, for operating the latch mechanism. The trigger mechanism includes a protrusion mounted thereon. The lever latch yet further includes a pawl, having a guide, mounted to the housing, and configurable between locked and unlocked positions. In the unlocked position, the guide is aligned with the protrusion to allow the trigger to operate the latch mechanism, and in the locked position, the guide is out of alignment with the protrusion and the protrusion contacts a surface on the pawl to thereby prevent the trigger from operating the latch mechanism.
Additional features, advantages, and embodiments of the invention may be set forth or apparent from consideration of the following detailed description, drawings, and claims. Moreover, it is to be understood that both the foregoing summary of the invention and the following detailed description are exemplary and intended to provide further explanation without limiting the scope of the invention as claimed.